Variable pressure cushion



April 30, 1957 R. ADAIR, JR

VARIABLE PRESSURE cusmou Filed March 24, 1955 Fob/n flz/a/r; Jr.

INVENTOR United States Patent i VARIABLE PRESSURE CUSHION Robin Adair, In, Dallas, Tex. Application March 24, 1955, Serial No. 496,541

7 Claims. (Cl. 128-33) This invention relates to variable pressure cushions and more particularly to an internal structure for a bed mattress, seat cushion or the like equipped with means operable to periodically relieve pressure areas imposed on the body or parts thereof in contact with the mattress or seat cushion, as the case may be and to induce circulation which otherwise would be retarded by prolonged recumbence or sitting.

The principal object of the invention is to provide a variable pressure apparatus designed primarily as a mattress or sleeping pad support or an internal structure for a mattress which is coextensive with the latter in length and width and designed to produce a motion simulating an undulating efiect, either continuously or periodically to relieve the body of a person reclining on the bed of pressures which otherwise may cause bed sores or ulcers diflicult to heal, especially on those who are bedridden through prolonged illnesses and further, the invention has physio-therapeutic value in inducing or stimulating blood circulation through the gentle massaging action of the movable elements of the device.

Another object of the invention is to provide a variable pressure device of the character set forth which consists basically of a frame made up of a plurality of sections hinged for relative angular displacement about their respective transverse axes, said frame supporting a multiplicity of transversely disposed, parallel cushions preferably of sponge rubber and supported on individual battens or slats, each secured to a sector gear which, in turn, is pivotally connected to the same hearing as the sector gear of an adjacent slat but movable independently thereof by engagement of the first sector gear with a worm on a section of a shaft extending lengthwise of the frame in parallelism with a like sectional shaft carrying worms accommodating the sector gear of the adjacent slat. The sections of the shafts are connected together at their ends by universal joints so that all sections of the shaft may be rotated by a motor irrespective of the angular positions of the frame sections, thus to cause the sector gears to oscillate and so move the slats and their cushions, the cushions of the series being adapted to move alternately in an arcuate path toward and away from the body of a person reclining on the bed or, in some cases, every other one of the cushions may so move while the companion cushions may remain stationary.

Another object of the invention is to provide a pressure relief cushion as set forth which may be adapted to provide comfort for those who are required to sit for long periods of time, such as bus operators and many others whose duties are pursued in a sitting position.

Other objects will appear as the description proceeds when considered with the annexed drawing, wherein:

Figure 1 is a top perspective view of a variable pressure cushion constructed according to the invention.

Figure 2 is a fragmentary sectional view showing two pairs of cushions and their supports and the actuating means therefor,.and

Figure 3 is a fragmentary top plan view showing the driving means for the shafts which actuate the cushions.

Continuing with a more detailed description of the drawing, reference numeral 10 denotes generally the variable pressure cushion frame which is made up of a head section 11, torso sections 12 and 13 and a foot section 14. The frame 10 may be constructed of four sections, as shown, three sections as common with conventional hospital beds or it may be made in rigid form without the adjustable sections, as desired.

As shown, the section 11 is composed of side members 15 and an end member 16. The inner ends of the side members 15 are pivotally joined by means of bolts 17 to one end of the side members 18 of the torso frame section 12. In like manner, the opposite ends of the side members 18 are pivotally' joined to adjacent ends of the side members 19 of the companion torso section 13 by means of bolts 20. The opposite ends of the side members 19 are pivoted by means of bolts 21 to the inner ends of the side members 22 of the foot section 14. The various sections of the frame may be raised and lowered in any conventional manner since this adjustment forms no part of the invention except in broad combination.

The invention consists of a plurality of slats or battens 23 (Figure 2) but which are preferably metal plates whose common length is substantially equal to or slightly less than the width of the space between the side rails of the several sections of the frame 10. Companion to the plates 23 are analogous plates 24, the plates 23 and 24 forming a pair whose juxtaposed edges are connected to the same pivot bolt or rod 25 by means of a hinge 26. The rods 25 extend transversely of the frame and their ends are journaled in the side members of the frame sections 11, 12, 13 and 14, as shown.

Vulcanized or otherwise secured to the upper surfaces of the plates 23 and 24 are sponge rubber cushions 27. These cushions and, of course, the supporting plates therefor, extend from one side to the other of the frame 10 and are disposed in sufficiently close relationship as to present a comfortable support for the body of a patient reclining thereon, especially when a comparatively thin bed pad is interposed between the surface and the patients body. However, sufilcient spacing of these cushions is provided to allow arcuate displacement of the individual cushions of one pair without interference with the nearest cushion of an adjacent pair of cushions, as indicated by the solid and dottedarrows in Figure 2. It is this movement of the selected groups of cushions against and away from the body of the patient that produces the comfort for which the invention was designed and relief from bed sores often suffered by bedridden persons. Also, by virtue of the same arrangement, alternate oscillative displacement of the cushions of each pair in the group of cushions induces or stimulates circulation of blood and otherwise contributes to the wellbeing of the patient.

To effect oscillation of the cushions according to the foregoing, each supporting plate 23 has welded or otherwise secured to its underside at each end a sector worm gear 28. The teeth of the gears 28 are engaged with the spirals of worm gears mounted on parallel sections 29 of a shaft which extends from the outer end of the head section 11 of the frame 10 to a point beyond the end of the foot section 14 where the ends of the shafts are journaled in gear cases 31 affixed to the end rail 32 and extending rearwardly of the foot section 14.

Each shaft 30 carries on its end a worm 33 which engages a worm gear 34 within the gear case 31 and a transverse shaft 35, carrying on its ends the worm gears 34 extends between the gear cases 31, as shown in Figure 3, and through a gear box '36 wherein a bevel gear l atented Apr. 30, 1957:

37 is mounted on the shaft 35 and meshes with a like I gear 38, .mounted on a square extension 39 of a shaft 40. The shaft 40 is hollow and squared to slidably receive the shaft 39 at one end and carries on its opposite end a bevel gear 41 which meshes with :a like gear 42, mounted on the armature shaft of an electric motor 43. The gears dl and llare encased-in a housing 44.

- The cushion supporting plates 24 companion .to the cushion supporting plates 23, are actuated bythe sector gears 4510 which-the plates 24 are welded or otherwise secured. The gears 45 are pivoted tothe same rods 25 and bythe same hinges 26 as the sector gears 28 but the teeth :of the gears .45 are in-engagement with respective sections 46 of a pair of shafts 47 which, like the shafts'30, are journaled at one end totheend-member 160i the head section 11 of the frame It) and at their oppositeends in gear gases-i43 secured to and extending rearwardly ofthe end rail 32 of the foot section 14 01? the frame 10. The shafts 47 are disposed inwardly of the shafts 30 and parallel therewith and each section of the shafts 47 carries worms 49 with which are engaged the sector worm gears 45.

. The ends of the sectional shafts 47 carry worms 50 (Figure 3) which engage worm gears 51 in the gear cases .52. A shaft 53 extends through the gear box 36 and .carries on its ends the worm gears 51 and on its midsection within the gear box 36 a bevel gear 54 is mounted which meshes with a like gear 55. The gear 55 is mounted on a square extension '56 (-Figure 1) of a hollow square shaft 57 which slidably receives the extension 56 and carries on its end a bevel gear 58 which meshes with a bevel gear 59, mounted on the armature shaft of a motor 60. The gears '58 and 59 are encased in the gear box 61 and both motors 43 and 60 are mounted on a common base 62 which may be supported in .anysuitable manner on the frameof the bed supporting the frame of the invention.

, The sections 46 of the shafts 47 are joined together at their ends by means of universal joints 63, as shown in Figure 2 and the sections of the shafts are equal in length to the sections of the frame 10 so that regardless of the angle to which the frame sections are adjusted, the shaft sections will turn freely. This is also true of the sections 29 of the pair of shafts '30 although the universal joints are concealed by the shaft 47 in Figure 2. It is evident from the foregoing that whether or not the sections 11, 12, 13 and 14 of the frame 10 are flat or disposed in angular positions, operation of the motor 43 will rotate the shaft 38 and thus cause the sector gears .28 to move in a counterclockwise direct-ion to tilt all of the cushion supporting plates 23 and consequently the cushions 27 thereon downwardly and below the common plane of the cushions in elevated or normal positions thereof. The motors 43 and 60 are of the reversible type and a control switch of any conventional design is contained in the box '64- (Figure 1) into which extends the service cord 65. Connections 66 are made between the control switch to the motors so that when the sector gears 28 reach their limit of travel in one direction the motor 43 will be automatically reversed to cause the sector gears 28 to travel in a clockwise di-rec tion. This is also true of the sector gears 45 and the motor 60 but it is intended that the timing be such that the plates 23 operate alternately with the plates 24 where it is desired to produce a massaging effect against the patients body to stimulate the circulation of blood. Operation of the motors in such a case is continuous over a period of time prescribed by a doctor.

When it is desired to relieve pressure against the pa tients body, at points where bed sores are developing orlikely to develop, one or the other group of cushions 27 are moved away from their normal supporting posit-ion and left in displaced position for as long as may be considered necessary by the doctor or nurse. it is readily apparent from the foregoing that a means 4 has been provided of a comparatively simple nature to increase the comfort of a bedridden person by relieving pressures on certain affected areas of the body and, when necessary or desirable, to massage the body to stimulate blood circulation. In the latter provision, the arrangement described, with certain adaptive alterations, the invention may be incorporated in a chair or seat to provide comfort for those whose trade or profession requires that they perform their duties in a sitting position.

Manifestly, the construction .as shown and described is capable of some modification and such modification as may be construed .to fall within the scope and meaning of the appended claims is also considered to be within the spirit and intent of the invention.

What is claimed is:

1. Apparatus of the character described comprising a frame having side and end members, a pair of parallel shafts extending the length of said frame adjacent each side member thereof, aplurality oftransverse longitudi nally spaced pairs of plates, the plates of each pair having their juxtaposed edges pivoted by acommon means to said side members for independent oscillation on said common means, a cushion affixed coextensively to each of said plates, .a worm gear sector afiixed to the undersurface of each of said plates, a worm on each shaft of said pair ofshafts engaged with each of said gear sectors and meansfor rotating a shaft of each pair of shafts alternately a predetermined distance in each direction to effect corresponding oscillation of said cushions.

2. Apparatus of the character described comprising a frame, a multiplicity of pairs of plates disposed transversely in said frame and spaced apart longitudinally thereof, a common means supporting the plates of-each pair of said platesin said frame for downward pivotal displacement on axes transverse to said frame, a cushion afixed to and coextensive with each of said plates and means for oscillating alternate plates of said series .to lower the cushions of the oscillated plates below the commen-plane of the companion cushions of said series.

3. The structure of claim 2 in which the frame is composed of a plurality of transversely pivoted sections and wherein said plate oscillating means consists of a pair of shafts each composed of a plurality of sections pivotally joined in end to end relationship and journaled in said frame adjacent each side thereof, a sector worm gear attached to and depending from each of said plates and a series of worms carried by each of said shaftsections and engaging said sector worm gears and electrically actuated means for alternately oscillating a shaft of each pair of shafts.

. 4. Apparatus of the character described comprising a frame, a group of transverse cushion plates pivotally mounted along one edge in said frame in longitudinally spaced relationship for rotation about their pivotal points, a cushion on each of said plates, at first shaft journaled in parallelism with each side of said frame and carrying a series of worms, a sector worm gear carried by alternate plates of said group and engaging said sector gears, 21 second shaft journaled in said frame in parallelism with each ofsaid first shafts and carrying longitudinally spaced Worms, a sector worm gear carried by each of the remaining plates of said group and engaging the worms of said second shafts and means for alternately oscillating said first and second shafts.

5. Apparatus of the character described comprising a frame, whose sides are in longitudinal sections pivoted in end to end relationship for relative pivotal displacement a group of pairs of transverse cushion plates the juxtaposed edges of the plates of each pair of plates being pivotally mounted on the sides of said frame in longitudinally spaced relationship for rotation about their pivotal points, a cushion on each of said plates, and means for rotating alternate plates of said group about their respective pivotal points. 7 I

6. A variable pressure cushion comprising a tram:

having parallel sides in. longitudinally extending and relatively pivoted sections, a group of narrow, elongate cushions extending transversely of said frame and spaced longitudinally thereof, a support for each of said cushions, said supports being in pairs, the supports of each pair being supported along juxtaposed edges on a common means between the sides of a section of said frame for pivotal displacement with respect one to the other to lower its opposite edge below the common plane of said group in normal position thereof and means for actuating the supports of alternate cushions of said group.

7. A variable pressure cushion comprising a frame, a group of narrow, elongate cushions extending transversely of said frame and spaced longitudinally thereof, a support for each of said cushions, each of said supports being supported along one edge in said frame for pivotal displacement with respect one to the other to lower its opposite edge below the common plane of said group in normal position thereof, means for actuating the supports of alternate cushions of said group, a first shaft journaled in parallelism with each side of said frame and carrying a series of worms, a sector worm gear carried by alternate supports of said group of cushions and engaging said sector gears, a second shaft journaled in said frame in parallelism, with each of said first shafts and carrying longitudinally spaced worms, a sector worm gear carried by each of the remaining supports of said group of cushions and engaging the Worms of said second shafts and means for alternately oscillating said first and second shafts.

References Cited in the file of this patent UNITED STATES PATENTS 1,404,482 Sawyer Jan. 24, 1922 

